Emil O. W. Kirkegaard – 2018 – Is national mental sport ability a sign of intelligence? An analysis of the top players of 12 mental sports [data]
… Zambian biochemist Chanda Chisala (2016 etc.) argued that Nigerian Scrabble performance was much higher than one would expect based on its national IQ estimate (given as 71.2 by Lynn and Vanhanen). His interpretation is that the tests are missing real ability present in this and other African populations. His study, however, was not systematic and did not include many other mental sports. The purpose of this study was to systematically examine the relationship between national skill at mental sports and national cognitive ability.
Ability in mental sports is g-loaded:
… a meta-analysis of studies of chess players and non-chess players round a mean group difference of .50 d (Sala et al., 2017). In another study, Quiroga et al (Ángeles Quiroga et al., 2015; see also Foroughi, Serraino, Parasuraman, & Boehm-Davis, 2016) administered 12 video games to 188 students as well as traditional standardized tests, and found that they measured nearly identical constructs (r’s .93 to .96).
The games used to test Chinda Chisala’s thesis:
For games, we included every esport listed at https://www.esportsearnings.com/games with at least 1,000 top players. This resulted in the inclusion of 8 games: DOTA 2 (dota2), League of Legends (lol), Counter-Strike: Global Offensive (csgo), Starcraft 2 (sc2), Counter-Strike (cs), Hearthstone (hs), Overwatch (ow), and Super Smash Bros. Melee (ssbm). Furthermore, we included major non-esports: Chess, Go, Poker and Scrabble.
Controlling for population size, performance in mental sports correlated r=0.79 with Lynn and Vanhanen’s published national IQs.
General gaming ability score and national IQ. Orange line = linear fit (top left), blue line = local regression fit (span = 1.00). Weighted by square root of population size.
Contra Chisala’s arguments that Nigeria’s IQ estimates were spuriously low due to its good performance in Scrabble, not only were its results concordant with its reported IQ levels of ~70, but it was also the poorest performing country in the world when controlling for population size.
In reality, there were actually just four major outliers. North Korea was the biggest negative outlier, presumably due to very low Internet penetration. South Africa, Brazil, and the United States were positive outliers, which Kirkegaard suggests could be a smart fraction effect.
So why Nigeria’s (relative to its IQ) outstanding performance on Scrabble?
Because it has by far the least mental sports loading (correlation with performance in other games) out of the twelve games, less so even than go, which is almost entirely constricted to East Asia.
With regards to the arguments by Chisala concerning Nigeria and Scrabble, we find no support for mismeasured Nigerian intelligence. It is true, as he noted, that Nigerians are much better at Scrabble than one would expect (standardized residual for Scrabble is 1.55, rank 3). However, Nigerians underperform on the remaining 11 sports (all residuals are negative), and the overall factor score of Nigeria (-1.39) is about what one would expect based on the current estimates of the country’s mean cognitive ability and the relation to national IQ. Indeed, based on a linear regression with just IQ, the standardized residual for Nigeria is only -0.16, meaning that the country performs very slightly worse at mental sports in general than one would expect based on its mean national intelligence. The predicted IQ of Nigeria was 73.1 based on a nonlinear model with just game performance as the predictor, Lynn and Vanhanen’s (2012) estimate was 71.2, and a recent large-scale study (n ≈ 11k) using Raven’s Standard Progressive Matrices found a mean IQ of 65.5 (Hur, Nijenhuis, & Jeong, 2017). The anomalously high Scrabble performance is not plausibly interpreted as hidden ability, but rather as a cultural specific preference for a specific sport.